The present invention relates generally to hood bumpers for automotive vehicles, and more particularly, to a hood bumper that manages energy from impacts to the vehicle hood.
Typically, hood bumper assemblies are mounted in an automotive vehicle between the frame of the vehicle and the bottom surface of a front portion of the vehicle hood. The primary purpose of hood bumper assemblies is to provide a support surface for the hood when it is closed. However, due to manufacturing tolerances in the assembly of an automotive vehicle, it is usually difficult for the automotive manufacturer to precisely predict where a particular hood will line up properly to particular vehicle fenders. In other words, while it is desirable for a closed vehicle hood to vertically line up with the surrounding body panels for pleasing aesthetics and for the hood to close at a particular height for the locking mechanism, the preferred vertical spacing between the hood and frame typically varies from vehicle to vehicle. Conventional hood bumpers solve this problem by providing various adjustable features that adjust the height of the top of the bumper assembly, and thus, the height of the vehicle hood relative to the vehicle frame. One example of an adjustable feature that may be used is a threaded engagement between various components of a bumper assembly.
Vehicle manufacturers and transportation regulators, however, are frequently concerned about the safety of automotive vehicles. One safety concern that has been expressed is that in highly dense communities, collisions between automotive vehicles and pedestrians can result in severe injuries to pedestrians who are hit by moving vehicles. One of the most common types of collisions between an automotive vehicle and a pedestrian involves the vehicle driving forward into a walking pedestrian so that the pedestrian falls onto and is hit by the hood of the vehicle. In these situations, a substantial portion of the moving vehicle's energy is transmitted to the pedestrian. In other words, while the vehicle may not suffer much damage, the pedestrian experiences the full force of the impact and can be severely injured.
Therefore, it would be desirable if automotive vehicles were equipped with a system that minimized the injury to pedestrians when collisions occur between vehicles and pedestrians. One area for improvement would be a vehicle hood arrangement that manages some of the impact energy during a collision instead of transmitting most of the impact energy to the pedestrian. This improvement might be possible by designing a hood bumper assembly that changes the height of the vehicle hood in a controlled manner during a collision to absorb energy. However, the majority of conventional hood bumper assemblies are not capable of substantially changing height or managing significant energy during an impact. In particular, the adjustable height features in most hood bumper assemblies are generally solid connections in use and cannot change height substantially when a direct force is applied to the hood. For example, while a conventional threaded connection in a bumper assembly can be used to adjust the height of a vehicle hood during manufacturing or later during an intentional adjustment by turning the threaded components relative to each other, a direct vertical load to the threaded connection will not cause any change in height of the bumper assembly. Thus, while conventional bumper assemblies can be intentionally adjusted in height, conventional bumper assemblies do not change height during an impact to absorb energy.
Accordingly, the inventors believe it would be desirable to provide a new vehicle hood bumper assembly that could change height in a controlled manner during a collision to absorb and manage the impact energy.